This application relates to underwater samplers and, in particular, to an improved suction sampler for collecting underwater biological specimens.
Underwater suction samplers have been used to collect samples of small aquatic flora and fauna. Unfortunately, sampling has been inconvenient or unsafe for divers using these types of samplers. For example, some samplers have limited mobility during operation due to their size and/or weight. Some samplers are heavy, or large and bulky, requiring two or more persons for transportation and operation. Some samplers weigh more than 8 lbs in water and 31 lbs in air and are more than 685 mm in length. Some of the large and heavy samplers cannot even be used by divers.
Other samplers lack mobility during operation because the body of the sampler or a component of the sampler must be placed on the bottom of the body of water and is left there while the sampler is being used. For example, a sampler may use a pneumatic pump that requires compressed air from a SCUBA tank. If the tank is left on the bottom, the length of the intake hose limits the diver to collecting samples in an area surrounding the tank. Also, some samplers use power sources that are not submergible and therefore must remain on shore or on a boat, using a cable to connect to the sampler.
Some samplers are hazardous for divers to use. For example, some samplers use air-driven power sources (such as drills) or air-driven pumps that use air from the diver's own air supply tank.
Some samplers require two hands for operation, for example, to arm or pump the device. Two-handed operation can make these samplers inconvenient and awkward to use when the hand not holding the sampler is occupied. Moreover, two-handed operation is a serious disadvantage, compromising diver safety, when the diver also needs to hold an item such as a lamp or light, or when the diver is required to read gauges or operate dive gear such as a buoyancy compensation device.
Some samplers are not continuous flow and therefore have limited sampling efficiency. Some samplers are restricted to a single sample or to a limited sample size, or have a difficult specimen transfer method.
Samplers that require pumping or constant rearming by the diver are labor intensive. Some even require multiple operators. For example, one operator may be required just to pump the sampler while another operator directs the intake hose. Also, samplers that must be manually armed/pumped may provide insufficient suction to capture certain organisms.
Samplers have been unable to take samples in many areas due to safety considerations or the type of substrate involved. Some underwater environments cannot be sampled due to safety concerns, including high velocity streams and water of low to zero visibility. Collecting samples from rock reef habitat is particularly difficult because of the inability of most samplers to gain access to surfaces with high rugosity. The same is true for heavily vegetated habitats. These types of areas can potentially be the most productive and unique habitats for benthic invertebrates (especially rare species) and larval fish.
The invention described herein avoids or ameliorates many of the shortcomings of current suction samplers mentioned above.